Substantiation of the main design parameters of the separation chamber of the pneumatic separator using various methods for calculating particle trajectories in the pneumoseparating channel

Abstract

The article presents a study of the influence of methods for calculating particle trajectories in the pneumatic separation channel (PSC) on the design parameters of the separation chamber (length and height of the exit window), completed in 2013-2021. The field of air flow velocities and trajectories of spring wheat seed material components in the separation chamber of fractioning pneumatic seed separator was constructed. The initial data for the calculation were the information obtained earlier when calculating the trajectories of particles in the PSC by various methods. The location at the outlet of the channel, the value and direction of the particle velocity vectors were determined by computer modelling using the Solidworks Flow Simulation software package and two experimental and theoretical methods. They took into account the real velocity field of the air flow with and without grain load. The obtained values of the design parameters are compared with the results of experimental studies of the separation chamber. It should be noted that the methods of calculating the trajectories of grain impurity particles have a significant impact on the length of the separation chamber and the height of the exit window. The maximum length of the separation chamber of 0.75 m will be required for computer modelling of the velocity field in the PSC. Much smaller values of 0.50 m and 0.45 m will be required when calculating the trajectories of particles in the PSC using the velocity field obtained by experimental and theoretical methods. During the experimental study of the separation chamber during the cleaning of wheat seeds, the optimal length of the separation chamber was determined to be 0.55 m with an exit window height of 0.30 m. Thus, the values of the design parameters of the separation chamber obtained by experimental and theoretical methods are the closest to experimental data, which makes it possible to recommend them for use at the design stage of pneumatic separators.